VCM not so efficient with blurry refractions? (fireflies bzzzzzz)

[CHRiTTeR]

Hi,

I'm new here and verry impressed thus far!

I was verry curious to see how the newish VCM method would perform (this is the main reason i decided to try corona).
Most tests i've seen use perfect glossy reflections/refractions and i find glossy/blurry glass sexy, i thought id test for myself how vcm handles it.
I found out it seems to be quite less efficient with blurry glass...

...or is it a bug? I wonder, because the fireflies have strange positioning (surrounding the object like a glow?)


Anyway, from all the tests i've seen with VCM i thought this render should've been 'done' by now, but clearly its not... (still rendering though, havent cancelled it yet).
Maybe it's me doing it wrong? Mostly using default settings though...


i have a small request/suggestion regarding this too: something like vray's 'affect shadows' option for refractive materials would be verry usefull for fast transparent shadows!

[Ondra]

this is most definitely a bug, can you post the scene?

[CHRiTTeR]

Sure, here it is.
I cleaned it up a little; removed hidden objects, layers and unused maps. I also converted the glass object to an editable mesh (it was an npower nurbs object).

The settings i changed (and that i remember) are:
Main corona settings:
- max ray depth to 50
- use bdir with vcm
- mat editor quality to 10
- change location of primary solver to d: (c: is my ssd so i dont like it being spammed with writes)
Depth of field/Motion blur settings
fstop to 2
sensor width to 36mm
VFB Settings:
Display AA to 2
[EXPERIMENTAL]Renderer: PT/VCM:
initial lookup radius to 3

Hope you can replicate it and find the little troublemaker!

[iliyang]

this is most definitely a bug, can you post the scene?

Please don't make me look bad and fix this ASAP :D

[Ondra]

Please don't make me look bad and fix this ASAP :D

Are you open to a little extortion? :D

[CHRiTTeR]

Had some more time to play around and apperently, the dof is also acting rather strange...

Heres the exact same scene, but i replaced the glass material with a near white diffuse one.
Left: dof on
Right: dof off
This time rendered using bdpt

Maybe its related to the other problem?

[Ludvik Koutny]

What exactly is wrong with that picture?

[CHRiTTeR]

What exactly is wrong with that picture?

With that last one?
Notice the hazy/foggy look around the dof... especially at the top of the object, where it is brightest.
Its almost like a glow or ghosting of the object going on.

I think some dof samples might be spread too much out or something?

[Ludvik Koutny]

What exactly is wrong with that picture?

With that last one?
Notice the hazy/foggy look around the dof... especially at the top of the object, where it is brightest.
Its almost like a glow or ghosting of the object going on.

I think some dof samples might be spread too much out or something?

Is that VCM or regular path tracing?

[CHRiTTeR]

What exactly is wrong with that picture?

With that last one?
Notice the hazy/foggy look around the dof... especially at the top of the object, where it is brightest.
Its almost like a glow or ghosting of the object going on.

I think some dof samples might be spread too much out or something?

Is that VCM or regular path tracing?

Those last 2 (with the white diffuse shader) were done with bdpt, the vcm option was not selected.

[Ludvik Koutny]

What exactly is wrong with that picture?

With that last one?
Notice the hazy/foggy look around the dof... especially at the top of the object, where it is brightest.
Its almost like a glow or ghosting of the object going on.

I think some dof samples might be spread too much out or something?

Is that VCM or regular path tracing?

Those last 2 (with the white diffuse shader) were done with bdpt, the vcm option was not selected.

Ah, i see... only progressive integrator is currently fully supported in Corona. If you do just tests of various integrators, then keep doing so, as it helps a lot. But if you want to produce some actual work, then progressive is way to go. BDPT and VCM are not production ready yet :)

[Polymax]

Do not use DOF with VCM, it not working properly.

[chilombiano]

this is most definitely a bug, can you post the scene?

Please don't make me look bad and fix this ASAP :D

Bulgarian technology! :p

[Ondra]

Fixed

[CHRiTTeR]

Awesome! I guess i cant download the version with the fix (yet?)